Brake mechanism



April 0, 1943. H. D. HUMPHREY BRAKE MECHANISM Filed March 24, 1941 @N N\w V kw QM a Q QW wm n NM NW mm, mm @MQ 3.1 woe/whom Patented Apr. 20,1943 BRAKE MECHANISM Homer D. Humphrey, Pittsburgh, Pa., assignor toBendix-Westinghouse Automotive Air Brake Company, Pittsburgh, Pin, acorporation of Delaware Application March 24, 1941, Serial No. 384,970(c1. 303-84) 20 Claims.

This invention relates to fluid pressure apparatus and more particularlyto a fluid pressure receiving system adapted for use in connection withfluid pressure braking systems for automotive vehicles.

In conventional fluid pressure braking systems for automotive vehicles,a fluid compressor is driven by the vehicle engine for supplying fluidpressure to a reservoir, from which the fluid pressure may be utilizedfor applying the vehicle brakes and also for operating auxiliaryequipment associated with the vehicle. In systems of this type, when theengine is rendered inoperative, and thereafter, when the source of fluidpressure is utilized in a manner outlined above, or in the event ofleakage in the system, the pressure of the fluid in the reservoir willfall below a value suflicient to maintain an application of the vehiclebrakes. Therefore, to safely operate a vehicle utilizing such a system,it is necessary to run the engine to drive the compressor, while thevehicle is at rest, until the fluid'in the. system builds up to apressure of sufficient value to give an effective brake application,before the vehicle can be safely driven.

Therefore, one of the objects of the present invention is to provide afluid pressure receiving system so arranged as to overcome thedisadvantages enume'rated heretofore.

Another object of the invention is to provide a fluid pressure receivingsystem having a nov :1 arrangement for isolating a source of fluidpressure from the system when the engine. which operates a mechanism forsupplying fluid pressure to the system, is rendered inoperative.

Still another object is to provide a fluid pressure receiving system ofthe above character wherein the construction is such as to allow theisolated source of fluid pressure to be utilized when the engine isrendered operative.

A further object of the invention is to provide, in a fluid pressurereceiving system, an arrangement for isolating a source of fluidpressure from the system when the engine, which operates a mechanism forsupplying fluid pressure to the system, is rendered inoperative, and forallowing the isolated source of fluid pressure to be utilized when theengine is rendered operative, and for preventing the flow of fluidpressure therefrom to other parts of the system when the pressure of thefluid in the other parts is below the pressure of the isolated fluid.

A still further object is to provide a novel arrangement of parts soconstructed and arranged as to be capable of ready inspection and repairand of such a nature that the same may be.

manufactured and installed upon existing fluid pressure systems at arelatively low cost.

Other objects and features of novelty of the invention will appear moreclearly from the 'ac-' companying drawing, which illustrates oneembodiment of the invention. It is to be expressly understood, however,that the drawing is for purposes of illustration only and is notdesigned as. a definition of the limits of the invention, referencebeing had for this purpose to the appended claims. 1

Referring more particularly to the drawing, a

fluid pressure brake system embodying the present invention is disclosedtherein as having a fluid compressor 10, driven by an engine H by meansof a belt l2, and controlled by a pressure governor l3, for supplyingfluid under pressure, through conduit M to reservoirs [Sand IS, thelatter being connected in series relation by means of a conduit ll.Conduits l8 and I9 are provided for supplying fluid pressure from thereservoir l6 to a brake valve 20, preferably of the selflapping type, asdisclosed in the patent toW. J

Andres and R. S. Sanford, No. 2,133,275, dated October 18, 1938, forControl mechanism, which is adapted to control the flow of fluidpressure to a plurality of brake actuators 2| and 22, through conduits23, 24 and 25.

As heretofore stated, it is one of the objects of the present inventionto provide means for isolating a source of fluid pressure from theconventional braking system when the engine which drives the compressorfor supplying a source of fluid pressure to the system is renderedinoperative, and for allowing the source of isolated fluid pressure toflow to the system when the engine is'rendered operative. Such means, asdisclosed in the drawing, comprises a reservoir 26 which is suppliedwith fluid pressure through conduits l8 and 21. A valvular device 28,which will be more fully described hereinafter, is adapted to controlthe flow of fluid pressure from the conduit l8 to the conduit 21 inresponse to the operation or the lack of operation of the engine I I. Aone-Way check valve 29 is positioned in conduit 18 for permitting theflow of fluid pressure from the reservoir I6 to the brake valve 20 whilepreventing flow in the reverse direction.

More particularly, the valvular mechanism 28 comprises upper and lowerbody portions 3fland 3| confining a pressure responsive element, such asa diaphragm 32, therebetween, thus defining a chamber 33, whichcommunicates with the atmosphere through a port 34 in the body portion3|, and a chamber 35 which is connected to an intake manifold 35 of theengine i I through conduit 31. The body portion 3| includes a downwardlyextending cylindrical portion 38 adapted to cooperate with a threadedplug 39 to define a chamber 40, which at all times communicates withconduit I8. The plug 39 includes a port 4| for providing a fluidconnection between the chamber 40 and the conduit 21. This fluidconnection is normally closed by the action of a valve member 42, whichis mounted for reciprocatory motion in the body portion 31. valve member42 is secured to the diaphragm 32 by any suitable means, and the otherend thereof has secured thereto a ball valve 43 which is adapted tocooperate with a valvoseat 44 of the plug 33. The ball valve 43 isnormally held against the valve seat 44 by the action of a spring 45 tonormally close the fluid connection between conduits l8 and 21.

In the normal position of th valvular mechanism 23, when there is novacuum present in the chamber 35 due to the lack of operation of theengine I I, the spring 45 urges the diaphragm 32 and themember 42downwardly, to bring the ball valve 43 into contact with the valve seat44 and thus close the fluid connection between conduits l8 and 21. Whenthe engine ll operates,

One end of the fluid under a relatively high pressure is thus vacuumwill be present in the intak manifold 36 and also in the chamber 35 ofthe valvular mechanism 28, due to the connection provided therebetweenby the conduit 31. The presence of vacuum in the chamber 35 will causethe diaphragm 32 and the valve member 42 to move upwardly as viewed inth drawinaagainst the re- 1 sistance of the spring 45, and thus move theball valve 43 away from the seat 44 and allow the 7 flow of fluidpressure from conduit 21, through the chamber 40 to conduit l3.

In the operation of the fluid pressure system heretoforedescribed, whenthe engine H is operating, the compressor l will'supply fluid pressureto the reservoirs l and l 6, through conduits l4 and I1, and hence tothe brake valve through conduit IS. The brake actuators 2| and" 22 maytherefore be energized with fluid lpreisure by operation of the brakevalve in a manner fully understood by those skilled in the art. Vacuumwill be present in the chamber of the valvular mechanism 28, and a fluidconnection between conduits I8 and 21 will, therefore, be established toallow the flow of fluid pressure from the reservoir Hi to the reservoir26 through conduit i8, chamber 39 of the valvular mechanism 23, andconduit 21. It will be readily understood that the pressure of the fluidin the reservoir 26 will be substantially equal tothe pressure of thefluid in the reservoirs l5 and I5, and that the supply of fluid pressureto all the reservoirs will be controlled 'by the pressure governor l3.

tem. If a brake application is made when the engine II is inoperative,the fluid pressure re quired therefor will be supplied from thereservoirs I5 and I6, and thus'reduce the pressure of the fluidcontained in these reservoirs. 'It can ever, when the engine, II isrendered operative,

the valvular mechanism is operated by the presence of vacuum in theintake manifold 36, to allow the flow of fluid pressure from thereservoir 26 to the brake valve 20, and a source oi immediately madeavailable for applying the vehicle brakes. The check valv 29 preventsflow .of fluid from the reservoir 26 to reservoir l5 under theseconditions. When the compressor 10 has operated a sufflcient length oftime to increase the pressure of the fluid in the reservoirs l5 and I6to a value greater than the pressure of th fluid in the reservoir 25,the check valve 29 will operate and allow the fluid pressure from thereservoirs l5 and I5 to supply the brake valve 20 in the conventionalmanner.

Thus, the present invention provides a fluid pressure receiving systemwherein a source of fluid pressure is isolated from the system when theengine, which operates a mechanism for supplying fluid pressure to thesystem, is rendered inoperative, and also provides means for allowingthe source of isolated fluidpressure to flow to certain portions of thesystem where the same maybe utilized when the engine is renderedoperative.

When such an arrangement is employed in a fluid pressure braking systemfor automotive vehicles, it-will be readily understood by those skilledin the art that numerous advantages result therefrom. For example, if abrake application is made after the engine is rendered inoperative, or,if the source of fluid pressure not isolated from the system is utilizedtobperate auxiliary equipment, the pressure of such fluid may be soreduced as to be of insuflicient value to give an effective brakeapplication. However, in the present system, a source of fluid pressureis available to give a maximum brake application the instant the engineis rendered operative, and, therefore, it is unnecessary for the'vehicle to remain at rest while the compressor operates to build up thepressure of the fluid in the system to a safe value.

Although only one embodiment of the invention has been illustrated anddescribed heretofore, it will be readily understood by those skilled inthe art that various other arrangements and modifications may beresorted to without adeparting from the spirit or the invention.Reference will, therefore, be had to the appended claims for adefinition of the limits of the invention.

What is claimed is:

1. A fluid pressure system comprising an engine, a fluid compressordriven by said engine, a plurality of reservoirs for receiving fluidpressure from said compressor, and means for preventing the flow offluid pressure from one or said reservoirs when the engine is renderedinoperative.

2. A fluid pressure system comprising an engine, a fluid compressordriven by said engine.

a reservoir for receiving fluid pressure from said compressor, a secondreservoir for receiving fluid pressure from the first named reservoir,

and means for preventing the flow of fluid pres val sure from saidsecond reservoir when the engine is rendered inoperative. y I

3. -In a fluid pressure system comprising .an

engine, a fluidcompressor drivenby said engine, a-plurality ofreservoirs for receiving fluid pressure from said compressor, means forpreventing the flow of fluid pressure from one of said reservoirs whenthe engine is rendered in- 4. In a fluid pressure system comprising anengine, a fluid compressor driven by said engine, and a reservoir forreceiving fluidpressure from said compressona second reservoir forreceiving'fiuidppressure from the first named; reser voir, and means forpreventingthe flow of fluid pressure from said second reservoir whenthe.

engine is rendered inoperative, said-means including means responsive tothe'operation of the engine for allowing the flow of fluid pressure fromsaid second reservoir.

5. In combination with a; fluid pressure sys tem having anengine, afluid-compressor driven by said engine, and a plurality oi reservoirsfor receiving fluid, pressure from said compressoiyj means for normallypreventing the flow of. fluid pressure from some of said, reservoirs,and means associated with said means for, allowing the flow of. fluidpressure fromsaidlastnamed reservoirs when the engine is operating I 6.In combination ..with a, fluid pressuresystem having an engine, a fluidcompressor drivenby said engine, and areservoir for receivingfluidpressure from said compressor, a second reservoir, a fluid connectionbetween ,the first named reservoir .and said second reservoir,;means insaid. connection for preventing the flow of fluid pressure from saidsecond reservoir tosaid first reservoir, means ior normally preventingthe v flow of fluid pressure fromsaid second reservoir,

and means responsive to theoperation of the engine for allowing the flowof fluidxplfessure from. said second reservoir. j

'7; In combination with by said engine, a reservoir for receivingdiuidpressure from said compressor, and adischarge conduit connectedto saidreservoir. an auxiliary reservoir, a fluid connection between said con--duit and last named reservoir, means; 315507;; ciated therewith fornormally closingsaidfcona; nection, and'means responsive to theoperation; of the engine for actuating said first named:

means for opening said connection.

8. In combination with a fluid prssure system having an engine, a fluidcompressor driven by said engine, a plurality of reservoirs forreceiving fluid pressure from said compressor, and a discharge conduitconnected to one of said reservoirs, an auxiliary reservoir, a fluidconnection between said conduit and said auxiliary reservoir, means fornormally closing said fluid connection, means responsive to theoperation of the engine for actuating said first named means for openingsaid connection, and means for preventing the flow of fluid pressurefrom said auxiliary reservoir to said first named reservoirs wherebywhen the engine is operating the discharge conduit is supplied withfluid pressure from said auxiliary reservoir when the pressure thereinis greater than the pressure of the fluid. in said first namedreservoirs,

a .fluid: pressure sysJ- tern having an engine, a fluidcompressor-driven fluid in the former is greater than the -9.In a fluidpressure system having an engine, a fluid compressor driven by saidengine, and 'a plurality of reservoirs connected in series relation, aconduit connecting the compressor to one reservoir of said series, adischarge conduit-connected to anotherreservoir of said series; anauxiliary reservoir, a second conduit forming afluid connection betweensaid auxiliar'yflreservoir and' said discharge conduit, means'in'saidsecond conduit for normally closinglsaidffluid connection, meansresponsive to the operation of the'engine for "actuating said 1 firstnamed means foropening said'fluid connection, and means for preventingthe flow of fluid pressure from said discharge'conduit to saidfirstfnainedrese'rvoirs when thepressure of the pressure of the fluid inthe latter.

10. In 'a', fluid pressure system having an engine,a' fluid compressordriven by said engine. a plurality of j reservoirs having a connectiontherewith for receiving fluid pressure from said compressor, anauxiliary reservoir having a connection with one of said first namedreservoirs for receiving fluid pressure from said reservoirs whenthe'engine is operating, and means for preventing'the flow of fluidpressure from said auxiliary reservoir when the engine is renderedinoperative.

ii, In a'fluid pressuresystem having an en gine,]a fluid compressordriven by said engine,

' "a reservoir for receiving fluidpressure from said compressor, adischarge conduit connected to saidfrescrvoin'a' second reservoirconnected to said-discharge conduit, means for preventing unicatio'nbetween said conduit and said sec ndfr eservoir when the engine isrenpei at'ive, 'andm'eans responsive to operationllof thejfengine foractuating said first n'ained means' for establishing communicationtherebetw'een;

v.12."Ii: ia fluid pressure system having an enginefa. fluid compressordriven by said engine, a plurality of reservoirs for receiving fluidpressure from said compressor, a discharge conduit connected to saidreservoirs, means for preventing the flow of fluid pressure from one ofsaid reservoirs to said discharge conduit when the engine is renderedinoperative, means for actuatingsaid'flrstnamedmeans for allowing theflow'of fluid pressure from said one reservoir 2:? to, said dischargeconduit when the engine is rendered operative, and means for preventingthe flow of fluid pressure from said other reservoirs to said dischargeconduit when the pressure of the fluid in the discharge conduit isgreater than the pressure of the fluid in said other reservoirs.

l3'fIn'a' fluid pressure braking system having a pressure responsivebrake actuator and a brake valve for controlling the flow of fluidpressure to said actuator, an engine, a fluid compressor driven by saidengine, a plurality of reservoirs for receiving fluid pressure from saidcompressor, a conduit for supplying fluid pressure from said reservoirsto said valve, an auxiliary reservoir connected to said conduit forreceiving fluid pressure from said first named reservoirs, means forpreventing the flow of fluid pressure from said auxiliary reservoir whenthe engine is rendered inoperative, means responsive to operation of theengine for actuating said means for allowing the flow of fluid pressureto and from said auxiliary reservoir to said conduit when the engine isoperating, and for preventing the flow oi, fluid pressure from saidauxiliary reservoir to said first named reservoirs.

14. In a fluid pressure braking system having a I pressure responsivebrake actuator and a brake valve for controlling the flow of fluidpressure to supplying fluid pressure to said main reservoir 7 and adevice for receiving fluid pressure from said reservoirs, of means forconnecting said main said actuatonan engine,"a fluid compressor- 1driven by said engine, a reservoir for receiving fluid pressure fromsaid compressor, means for supplying fluid pressure from said reservoirtosaid valve, a second reservoir incommunication with said valve andadapted to'receive fluid'pressure from said first named reservoir, meansfor preventing the flow of fluid pressurefrom said second reservoir-tosaid valve when the engine is rendered inoperative, means responsive toop-' eration of the engine for actuating said second named means forallowing the flow oi fluid pressure fromsaid second reservoir to saidvalve, and

7 means for preventing the flow oi fluid pressure. I from said secondreservoir to said first reservoir when the pressure of the fluid in saidfirst reser- -'voir is less than the pressure of the fluid in saidsecond reservoir. x 7

15. In a fluid pressure'system having an engine, a fluid compressordriven by said engine, a plurality of reservoirs, a pluralltyo! conduitsconnecting said reservoirs in series relation for receiving fluidpressure from said compresson'a discharge conduit connected to saidseries, means ,for allowing the flow or fluid pressure to'all of saidreservoirs whenthe engine is operating,

means for preventing the flow or fluid pressure to one oi saidreservoirs. when the engine is rendered inoperative, wherebyisaiddischarge conduit is supplied with .fluid pressure from other ofsaidreservoirs, and means for actuating said second named means forpreventing the flow of fluid pressure to saidotherreservoirs'from saidall times, and means associated with the connection between saidauxiliary reservoir and the device and having a connectionwith andbeing; controlled by the operation of the power'means one reservoir whenthe engine is operatingand when the pressure of the fluid in said oneresera voir is greater than the pressure or the fluid in said otherreservoirs, whereby said discharge conduit is supplied with fluidpressure from said one reservoir.

16. In combination with a fluid pressure system having a pair ofreservoirs and power means including a compressor for supplying fluidPIGS? 1 sure to said reservoirs, means for serially connecting said,reservoirs, means rorpreventing the.

flow of fluid pressure between said reservoirs in' one direction;andrmeans havinga connection with and'controlled by the operation of thepower means for preventing the flow or fluid'pressure from the otherreservoir in said series when the power means is inoperative.

17. The combination with a fluid pressure system having a mainreservoir, an auxiliary reservoir, power means including a compressorfor reservoir with the device,-means for: connecting said auxiliaryreservoir with the device, means for preventing the flow oi fluidpressure from v 1 said auxiliary reservoir to said main reservoir at, r

for preventingcommunication between the aux-.

iliary reservoir and the device when the power means is not operating.

18. The combination with a fluid pressure system having a pair orreservoirs, power means including a compressor for supplying fluidpressure to said reservoirs and a device to be operated by 1 fluidpressure therefrom, or means for seriallyconnecting said reservoirs withsaid power means.

meansfor connecting said reservoirs in parallel withrsaid device, andmeans controlled'by the operation or said power means: and having a 7connection therewith for rendering one'of' said parallel connectionsineilective exceptwhen the. power means is supplying fluid pressure tothe,

reservoirs.

and having a connection therewith. for supplying fluid pressure to thedevice from the-other reservoir only when the power means is oper 20.The I combination-with power actuated means including a compressor forsupplyingfluld, pressure, a pair or reservoirs for 'receivingfluidpressure therefrom and a device'to beactuated by fluid pressure fromsaid reservoirs," or means 7 for serially connecting said reservoirs"for ireceiving fluid pressure from said flrst'named means and forc'onnecting said reservoirs in parallel with said device, means .101'. 7preventing the flow oi 'fluid pressure between said reservoirs in onedirection, and means controlled by the operation or saidflrst namedmeans and having a, connec-l 1 tion therewith for preventing the flowfof fluid j 'pressure from one of saidreservoirs to said de vice when thefirst named means is inoperative to supplyfluid pressureto saidreservoirs.

HOMER D. HUMPHREY.

, ative to supply fluid pressure to. said one reser

